The invention described and claimed herein relates to the field of biologically active tetracyclic compounds, and the subfields for methods of preparing such compounds, and pharmaceutical compositions containing these tetracyclic compounds.
Corresponding 1,4-di-aza-cyclohexane compounds are known and are described in U.S. Pat. No. 3,534,041 and U.S. Pat. No. 3,701,778. However, they are characterized by possessing CNS-stimulating activity rather than CNS-inhibiting activity, in addition to pronounced antihistamine and anti-serotonin activity. Hence, one skilled in the art would, without experimentation, have expected the novel compounds (I) described below to have similar properties.